Metabolism: what you know and what might surprise you Lecture Lab
Chapter 5 Streak plate subcultures Enzymes Staining: Gram stain Aerobic and anaerobic Motility respiration Pre-labs Review Gram Staining and other assays
Microbial metabolic diversity- how is it possible?
Recipe: 500 ml mud from beach at low tide 10 g filter paper (cellulose)
1 g NH4Cl 1 g KH2PO4 1 g CaSO4 water jan.ucc.nau.edu/.../lectures/lec23/lec23.html
Metabolism is possible through enzymatic diversity
Figure 5.2 Enzyme structure
Cofactors
Ions of iron, zinc, magnesium and calcium
Coenzymes
Nicotinamide adenine dinucleotide (phosphate) - NAD+/ NADP+ from B vitamin niacin
Flavin adenine dinucleotide- FAD from B vitamin riboflavin Figure 5.3 Effects on enzyme activity: temp and pH
Figure 5.6 Effects on enzyme activity: competitive inhibition
Example:
Sulfa drugs
Figure 5.7 Effects on enzyme activity: noncompetitive inhibition
Example: Mercury poisoning
Figure 5.7 Effects on enzyme activity: feedback inhibition
Figure 5.8 Pit Stop
Why would it be beneficial to have a fever during a bacterial infection? Why is a fever over 40° C often life threatening? Metabolism: catabolism and anabolism anabolism~ dehydration synthesis~ condensation
catabolism~ hydrolysis~ decomposition
Figure 2.8 Redox reactions- the basis of metabolism Redox reactions- the basis of metabolism
O I L R I G Major electron carriers
- FAD accepts two H+/e- FADH2
- NAD+ accepts one H+/ e- NADH
- Cytochromes accept e-
Phosphorylation reactions or HOW WE MAKE ATP
1. Substrate level phosphorylation
2. Oxidative phosphorylation
3. Photophosphorylation
Phosphorylation reactions or HOW WE MAKE ATP
?
1. Substrate level phosphorylation
2. Oxidative phosphorylation
3. Photophosphorylation
1. Substrate level phosphorylation Phosphorylation reactions or HOW WE MAKE ATP
?
1. Substrate level phosphorylation
2. Oxidative phosphorylation
3. Photophosphorylation
2. Oxidative Phosphorylation (Carbohydrate catabolism)
Fermentation Aerobic respiration - Alcohol ferm Anaerobic respiration - Lactic acid ferm - Mixed acid ferm - Butanediol ferm - Butylic/butyric acid - Etc. Let’s review: aerobic respiration Steps: 1. Glycolysis
1a. Pentose phosphate pathway 1b. Entner-Doudoroff pathway
2. Transition/preparatory step
3. Krebs Cycle/ TCA
4. Electron transport chain (ETC)
Total energy output:
How does the ETC make so much ATP?
Figure 5.16 What is a terminal electron acceptor?
In aerobic respiration= oxygen
Bacteria Electron acceptor Products
In Pseudomonas, – – NO3 NO2 , N2 + H2O anaerobic respiration= Bacillus
– no oxygen Desulfovibrio SO4 H2S + H2O
2 – methanogens CO3 CH4 + H2O
Figure 5.14 (2 of 2) Anaerobic respiration
Steps: 1. Glycolysis
1a. Pentose phosphate pathway 1b. Entner-Doudoroff pathway
2. Intermediate step
3. Krebs Cycle/ TCA
4. Electron transport chain (ETC)
Total energy output:
Independent Study
1. Review the light dependent and light independent reactions of photosynthesis (see Figure 5.25 and 5.26).
***Print out and bring APO-2: A Metabolism Case Study for next class.
More cool microbial metabolism
Lecture Lab
Continue Chapter 5 Acid fast, spore and capsule stains Fermentation Photophosphorylation Pre-labs Microbial metabolic diversity Using the Spectrophotometer and Exam Review APO 2: Case study in fermentation Let’s review: aerobic respiration Steps: 1. Glycolysis 2 substrate level ATP 2 NADH 1a. Pentose phosphate pathway 1b. Entner-Doudoroff pathway 2. Transition/preparatory step
2CO2 2 NADH 3. Krebs Cycle/ TCA 2 substrate level ATP
4 CO2 6 NADH
2 FADH2 4. Electron transport chain (ETC) 34 ATP
Total energy output:
38 ATP (prokaryotes) 36 ATP (eukaryotes) Figure 5.16 What is a terminal electron acceptor?
In aerobic respiration= oxygen
Bacteria Electron acceptor Products
Pseudomonas, – – NO3 NO2 , N2 + H2O In Bacillus anaerobic respiration= – no oxygen Desulfovibrio SO4 H2S + H2O
2 – methanogens CO3 CH4 + H2O
Figure 5.14 (2 of 2) Anaerobic respiration
Steps: 1. Glycolysis 2 substrate level ATP 2 NADH 1a. Pentose phosphate pathway 1b. Entner-Doudoroff pathway 2. Intermediate step
2CO2 2 NADH 3. Krebs Cycle/ TCA partially utilized 4. Electron transport chain (ETC) partially utilized
Total energy output:
Varied, between 2-38 ATP Varieties of fermentation
Steps:
1. Glycolysis 2 substrate level ATP 2 NADH
2. Fermentative pathway
**Lactic acid fermentation Homolactic OR Heterolactic **Alcoholic fermentation Additional fermentation pathways
Fermentative microbes
See Figure 5.18 and Table 5.4 Comparison of catabolic efficiency Reminder: other organic molecules can be used for ATP production
Figure 5.21 What good are alternative metabolisms to us?
Pt. Loma Wastewater Treatment Plant
http://www.sandiego.gov/mwwd/facilities/ptloma.shtml How does it happen?
Figure 27.18 Phosphorylation reactions or HOW WE MAKE ATP
1. Substrate level phosphorylation
2. Oxidative phosphorylation
3. Photophosphorylation
3. Photophosphorylation
Photo reactions of photosynthesis Photo reactions: cyclic and non-cyclic photophosphorylation
Cyclic outcomes
e- thru ETC produce ATP e- recycle back to chloropyll
Non-cyclic outcomes
e- thru ETC produce ATP Terminal acceptor is NADP+ Photoylsis recycles e- to clorophyll: + H2O 2H + ½O2 + 2e-
Figure 5.24 What is the ATP and NADPH used for?
Synthesis reactions Figure 5.26 Varieties of photosynthesis Example of anoxygenic photosynthesis Nutritional classification of organisms
Figure 5.28 Independent Study 1. Test yourself on the energy and carbon needs of microbes. Use the blank flowchart in the following slide and fill in the appropriate nutritional categories. Once you have done this, use the flowchart to answer question #2.
2. Determine carbon source, energy course, and type of metabolism (i.e. aerobic or anaerobic respiration, fermentation, oxygenic or oxygenic photosythesis) for the following organisms:
a. Pseudomonas, an aerobic chemoheterotroph b. Clostridium, an anaerobic chemoheterotroph c. Spirulina, an oxygenic photoautotroph d. Ectothiorhodopsin, an anoxygenic photoautotroph e. Nitrosomonas, a nitrogen oxidizing chemoautotroph
3. Study for Exam 1
All organisms
Energy source
Carbon source Carbon source
Final electron acceptor Use H2O to reduce CO2?